This invention relates to the formation of a joint between two parts, such as pipes or conduits, by a cold weld process utilizing the forces of shrink fit to create stresses, in excess of yield of the material, acting on small area pads to cold weld the parts together.
This invention also provides a means for compensating for misalignment of the parts as they are initially brought together by the use of bellows. Later, the bellows is provided with a backing material which gives strength and rigidity to that part of the joint.
Finally, this invention teaches how this joint can be made up and disconnected at a location remote from an operator.
The formation of interference fits between metal parts is a technique which has been practiced for many years. This technique utilizes a heating or cooling of one of the parts to form the shrink fit and are shown by way of example in the U.S. Patents to Harrison et al., U.S. Pat. No. 4,035,007, and U.S. Pat. No. 4,198,007, where a coupling is heated and cooled to permit the pipe ends to be installed and removed; in the U.S. Pat. No. 3,579,805 to Kast where an interference fit is formed by heat treatment; in the U.S. Pat. No. 3,469,862 to Conibeer where liquid metal leaks through telescoping parts and is frozen to seal the parts together. In the Patent to Conibeer, bellows are also used to contain an inert gas which freezes the parts, and bellows are also used in the U.S. Pat. No. 3,705,734 to Rajakovics.
However, it will be apparent to those skilled in the art from the drawings and the written disclosure of this invention hereinafter that the prior art does not disclose a cold weld joint and the method of forming same using the forces of shrink fit; the prior art does not show the use of bellows as a means for compensating for misalignment; nor does the prior art show how a joint can be made up and disconnected at a remote location.